1. Field of the Invention
The present invention relates to an image processing system, and more particularly, to a window system suitable for processing images which are displayed on a plurality of display devices.
2. Related Background Art
In a conventional image processing system, an image-only display is connected to an engineering work station (abbreviated to EWS), and images are displayed on the image-only display. In that case, a bit-map display may also be used to display images. Generally, in the case of display of images on a display, such as an on the image-only display, an image-only display display processing routine is called to perform display. Thus, when images are to be output to the EWS, a display processing routine offered by the EWS is called. In the case of the EWS, a multi-window system may be activated, and images may also be displayed in the windows. The multi-window system may be incorporated in the operating system (abbreviated to OS) of the EWS or be provided separately from the operating system as an individual process.
On such a system, display management may be performed, e.g., the display destination may be changed over from, for example, the image-only display to the window. Alternatively, the image may be temporarily saved on the display of the EWS in the form of an icon (a symbol). The associated functions may be incorporated in the process which implements the window system or in the operating system.
However, in that system, when changes occur in the system configuration, including the image processing hardware, the number of planes on the bit-map display of the EWS, and the number of displays connected to the system, the program which performs display and management of images, such as the process which implements the window system or the operating system, must be modified or altered. However, modification or alteration of the program itself is a troublesome task, and increases production cost. At the same, the portability and modularity of the program are degraded.